CA2255356C - Gelling polymers for wellbore service fluids - Google Patents
Gelling polymers for wellbore service fluids Download PDFInfo
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- CA2255356C CA2255356C CA002255356A CA2255356A CA2255356C CA 2255356 C CA2255356 C CA 2255356C CA 002255356 A CA002255356 A CA 002255356A CA 2255356 A CA2255356 A CA 2255356A CA 2255356 C CA2255356 C CA 2255356C
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- wellbore
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- 229920000642 polymer Polymers 0.000 title claims abstract description 42
- 239000012530 fluid Substances 0.000 title claims abstract description 40
- 238000004132 cross linking Methods 0.000 claims abstract description 21
- 239000003431 cross linking reagent Substances 0.000 claims abstract description 9
- 239000000126 substance Substances 0.000 claims abstract description 8
- 238000000034 method Methods 0.000 claims description 9
- 230000015572 biosynthetic process Effects 0.000 claims description 7
- ISWSIDIOOBJBQZ-UHFFFAOYSA-N phenol group Chemical group C1(=CC=CC=C1)O ISWSIDIOOBJBQZ-UHFFFAOYSA-N 0.000 claims description 6
- 238000006243 chemical reaction Methods 0.000 claims description 4
- 125000003158 alcohol group Chemical group 0.000 claims description 2
- 230000005494 condensation Effects 0.000 claims 1
- 238000009833 condensation Methods 0.000 claims 1
- 125000002485 formyl group Chemical class [H]C(*)=O 0.000 claims 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 abstract description 11
- 239000000499 gel Substances 0.000 description 16
- WSFSSNUMVMOOMR-UHFFFAOYSA-N Formaldehyde Chemical compound O=C WSFSSNUMVMOOMR-UHFFFAOYSA-N 0.000 description 9
- 239000000203 mixture Substances 0.000 description 8
- FUGYGGDSWSUORM-UHFFFAOYSA-N 4-hydroxystyrene Chemical compound OC1=CC=C(C=C)C=C1 FUGYGGDSWSUORM-UHFFFAOYSA-N 0.000 description 6
- HGINCPLSRVDWNT-UHFFFAOYSA-N Acrolein Chemical compound C=CC=O HGINCPLSRVDWNT-UHFFFAOYSA-N 0.000 description 6
- 239000004215 Carbon black (E152) Substances 0.000 description 6
- 238000005755 formation reaction Methods 0.000 description 6
- 229930195733 hydrocarbon Natural products 0.000 description 6
- 150000002430 hydrocarbons Chemical class 0.000 description 6
- 238000004519 manufacturing process Methods 0.000 description 6
- 150000001299 aldehydes Chemical class 0.000 description 5
- 229920001577 copolymer Polymers 0.000 description 5
- HRPVXLWXLXDGHG-UHFFFAOYSA-N Acrylamide Chemical compound NC(=O)C=C HRPVXLWXLXDGHG-UHFFFAOYSA-N 0.000 description 4
- 239000004971 Cross linker Substances 0.000 description 4
- 239000000178 monomer Substances 0.000 description 4
- 229920002401 polyacrylamide Polymers 0.000 description 4
- -1 adipate ions Chemical class 0.000 description 3
- 241000364021 Tulsa Species 0.000 description 2
- 230000008901 benefit Effects 0.000 description 2
- 238000010382 chemical cross-linking Methods 0.000 description 2
- BFGKITSFLPAWGI-UHFFFAOYSA-N chromium(3+) Chemical compound [Cr+3] BFGKITSFLPAWGI-UHFFFAOYSA-N 0.000 description 2
- 229920006037 cross link polymer Polymers 0.000 description 2
- 238000011161 development Methods 0.000 description 2
- 229920006158 high molecular weight polymer Polymers 0.000 description 2
- 229910001410 inorganic ion Inorganic materials 0.000 description 2
- 239000002085 irritant Substances 0.000 description 2
- 231100000021 irritant Toxicity 0.000 description 2
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 2
- 230000035699 permeability Effects 0.000 description 2
- 230000008569 process Effects 0.000 description 2
- 238000011084 recovery Methods 0.000 description 2
- 238000011282 treatment Methods 0.000 description 2
- 229920003169 water-soluble polymer Polymers 0.000 description 2
- QTBSBXVTEAMEQO-UHFFFAOYSA-M Acetate Chemical compound CC([O-])=O QTBSBXVTEAMEQO-UHFFFAOYSA-M 0.000 description 1
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 description 1
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 1
- 229920002907 Guar gum Polymers 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- 230000002378 acidificating effect Effects 0.000 description 1
- 238000013459 approach Methods 0.000 description 1
- 239000007864 aqueous solution Substances 0.000 description 1
- 230000000903 blocking effect Effects 0.000 description 1
- KGBXLFKZBHKPEV-UHFFFAOYSA-N boric acid Chemical compound OB(O)O KGBXLFKZBHKPEV-UHFFFAOYSA-N 0.000 description 1
- 239000004327 boric acid Substances 0.000 description 1
- 150000007942 carboxylates Chemical group 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 229910052804 chromium Inorganic materials 0.000 description 1
- 239000011651 chromium Substances 0.000 description 1
- 230000000295 complement effect Effects 0.000 description 1
- 238000006482 condensation reaction Methods 0.000 description 1
- 238000005553 drilling Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 238000001879 gelation Methods 0.000 description 1
- 150000004676 glycans Chemical class 0.000 description 1
- 229960002154 guar gum Drugs 0.000 description 1
- 235000010417 guar gum Nutrition 0.000 description 1
- 239000000665 guar gum Substances 0.000 description 1
- 231100001261 hazardous Toxicity 0.000 description 1
- 239000000017 hydrogel Substances 0.000 description 1
- 229920001477 hydrophilic polymer Polymers 0.000 description 1
- 238000011065 in-situ storage Methods 0.000 description 1
- 238000010348 incorporation Methods 0.000 description 1
- 238000002347 injection Methods 0.000 description 1
- 239000007924 injection Substances 0.000 description 1
- 125000003010 ionic group Chemical group 0.000 description 1
- 150000002500 ions Chemical class 0.000 description 1
- 230000002427 irreversible effect Effects 0.000 description 1
- 239000003446 ligand Substances 0.000 description 1
- 239000011159 matrix material Substances 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 239000003345 natural gas Substances 0.000 description 1
- 150000002989 phenols Chemical class 0.000 description 1
- 229920000058 polyacrylate Polymers 0.000 description 1
- 229920000867 polyelectrolyte Polymers 0.000 description 1
- 229920001282 polysaccharide Polymers 0.000 description 1
- 239000005017 polysaccharide Substances 0.000 description 1
- 229920002451 polyvinyl alcohol Polymers 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 230000000246 remedial effect Effects 0.000 description 1
- 239000004576 sand Substances 0.000 description 1
- 238000012216 screening Methods 0.000 description 1
- 241000894007 species Species 0.000 description 1
- 125000001273 sulfonato group Chemical group [O-]S(*)(=O)=O 0.000 description 1
- 231100000331 toxic Toxicity 0.000 description 1
- 230000002588 toxic effect Effects 0.000 description 1
- 231100000419 toxicity Toxicity 0.000 description 1
- 230000001988 toxicity Effects 0.000 description 1
- 230000002110 toxicologic effect Effects 0.000 description 1
- 231100000027 toxicology Toxicity 0.000 description 1
- GBNDTYKAOXLLID-UHFFFAOYSA-N zirconium(4+) ion Chemical compound [Zr+4] GBNDTYKAOXLLID-UHFFFAOYSA-N 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
- C09K8/00—Compositions for drilling of boreholes or wells; Compositions for treating boreholes or wells, e.g. for completion or for remedial operations
- C09K8/02—Well-drilling compositions
- C09K8/03—Specific additives for general use in well-drilling compositions
- C09K8/035—Organic additives
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
- C09K8/00—Compositions for drilling of boreholes or wells; Compositions for treating boreholes or wells, e.g. for completion or for remedial operations
- C09K8/50—Compositions for plastering borehole walls, i.e. compositions for temporary consolidation of borehole walls
- C09K8/504—Compositions based on water or polar solvents
- C09K8/506—Compositions based on water or polar solvents containing organic compounds
- C09K8/508—Compositions based on water or polar solvents containing organic compounds macromolecular compounds
- C09K8/5086—Compositions based on water or polar solvents containing organic compounds macromolecular compounds obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds
Landscapes
- Chemical & Material Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Organic Chemistry (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Addition Polymer Or Copolymer, Post-Treatments, Or Chemical Modifications (AREA)
- Processing Of Solid Wastes (AREA)
Abstract
A wellbore service fluid comprising polymers having cross--linking groups capable of forming chemical bonds with other polymers without additional monomeric cross-linking agents is described, particularly applicable to water control operations.
Description
57.268 CA/NO
GellinQ polymers for wellbore service fluids The present invention relates to polymer based gelling composition for wellbore service fluids. More particularly it relates to polymer based gelling composition for reducing the flow of subterranean aqueous fluids into a well while maintaining the hydrocarbon production.
BACKGROUND OF THE INVENTION
Various types of wellbore fluids are used in operations related to the development, completion, and production of natural hydrocarbon reservoirs. The operations include fracturing subterranean formations, modifying the permeability of subterranean formations, or sand control. Other applications comprise the placement of a chemical plug to isolate zones or complement an isolating operations. The fluids employed by those operations are known as drilling fluids, completion fluids, work over fluids, packer fluids, fracturing fluids, conformance or permeability control fluids and the like.
Of particular interest with regard to the present inventions are fluids for water control applications, as during the life cycle of a hydrocarbon well, e.g., a well for extracting oil or natural gas from the'Earth, the producing well commonly also yields water. In these instances, the amount of water produced from the well tends to increase over time with a concomitant reduction of hydrocarbon production. Frequently, the production of water becomes so profuse that remedial measures have to be taken to decrease the water/hydrocarbon production ratio. As a final consequence of the increasing water production, the well has to be abandoned.
57.268 CA/NO
GellinQ polymers for wellbore service fluids The present invention relates to polymer based gelling composition for wellbore service fluids. More particularly it relates to polymer based gelling composition for reducing the flow of subterranean aqueous fluids into a well while maintaining the hydrocarbon production.
BACKGROUND OF THE INVENTION
Various types of wellbore fluids are used in operations related to the development, completion, and production of natural hydrocarbon reservoirs. The operations include fracturing subterranean formations, modifying the permeability of subterranean formations, or sand control. Other applications comprise the placement of a chemical plug to isolate zones or complement an isolating operations. The fluids employed by those operations are known as drilling fluids, completion fluids, work over fluids, packer fluids, fracturing fluids, conformance or permeability control fluids and the like.
Of particular interest with regard to the present inventions are fluids for water control applications, as during the life cycle of a hydrocarbon well, e.g., a well for extracting oil or natural gas from the'Earth, the producing well commonly also yields water. In these instances, the amount of water produced from the well tends to increase over time with a concomitant reduction of hydrocarbon production. Frequently, the production of water becomes so profuse that remedial measures have to be taken to decrease the water/hydrocarbon production ratio. As a final consequence of the increasing water production, the well has to be abandoned.
57.268 CA/NO
In many cases, a principal component of wellbore service fluids are gelling compositions, usually based on cross-linkable polymers.
Polymer gels have been widely used for various wellbore service fluids, including fluids for conformance control of naturally fissured/fractured reservoirs. For an overview of existing polymer compositions, reference is made to the United States patent Nos. 5,486,312 and 5,203,834 which also list a number of patents and other sources related to gel-forming polymers.
Among the numerous cross-linking agents are inorganic ions (or ionic complexes) or polar organic molecules. When the polymer contains ionic groups such as carboxylate or sulphonate functions the polymer chains can be cross-linked by inorganic ions such as chromium(III) or zirconium(IV), frequently in the presence of monomeric ligands, such as acetate or adipate ions.
Furthermore, the gelation of high molecular weight polymers (Mw >
106 g/mol) has been extensively used in the development of water-based treatment fluids for water control is further described for example by R. D. Sydansk in "Acrylamide-polymer/chromium(III)-carboxylate gels for near weilbore matrix treatments", 7th SPE Symp. Enhanced Oil Recovery, Tulsa, Ok., April 1988, SPE/DoE 20214, or by R. S. Seright in: "Placement of gels to modify injection profiles", SPE/DoE Symp. Enhanced Oil Recovery, Tulsa, Ok., April 1994, SPE 27740. Typically for those methods, an aqueous solution of a high molecular weight polymer, such as a polyacrylamide/polyacrylate copolymer (a so-called partially-hydrolysed polyacrylamide), is gelled in situ in a porous formation using a metal cross-linker such as Cr3+ or small water-soluble organic cross-linkers such as formaldehyde and formaldehyde/phenol. Other water-soluble polymers such as poly(vinyl alcohol), the polysaccharide guar gum and the copolymer poly(vinylpyrrolidone-co-2-acrylamido-2-methyl-l-propanesulphonic acid) which can be cross-linked with a variety of cross-linking agents such as Zr4+ and boric acid.
A more recent approach is described by A. Keller and K. A. Narh in: "The effect of counerions on the chain conformation of polyelectrolytes, as assessed by extensibility in elongational flow: the influence of multiple valency", J. Polym. Sci.: Part B: Polymer Phys., 32, 1697-1706 (1994). It includes the cross-linking of poly(sodium 4-styrenesulphonate) using A13+ ions to form a gel. The concentration of the high molecular weight hydrophilic polymers used to form hydrogels is typically in the range 3-10 g/1.
Copolymers containing polar and non-polar segments are described for example in U.S. Patent No. 4,776,398. The copolymers are cross-linked in subterranean formations so as to control the permeablity of the formation layer before injecting a driving fluid into injector wells.
SUMMARY OF THE INVENTION
The present invention provides novel polymer for wellbore service fluids. Specifically the invention introduces novel cross-linking methods for such polymers avoiding the use of environmentally potentially hazardous agents. More specifically the invention provides polymer compositions for water control operations in hydrocarbon wells.
In one aspect, the invention provides a wellbore service fluid comprising polymers having a small amount of one or more repeat units incorporating a cross-linking group capable of forming chemical bonds with other polymers without additional monomeric cross-linking agents said fluid to be injected from surface location into a subterranean - 3a -location and being capable of forming a gel at said subterranean location.
In a further aspect, the invention provides a method of treating a subterranean formation penetrated by a wellbore, said method comprising the steps of preparing a wellbore service fluid comprising polymers having a small amount of one or more repeat units incorporating a cross-linking group capable of forming chemical bonds with other polymers without additional monomeric cross-linking agents;
injecting said wellbore service fluid from surface location through said wellbore into a subterranean location; and letting said service fluid form a gel at said subterranean location.
According to the invention there are provided a wellbore service fluid comprising polymers having cross-linking groups capable of 57.268 CA/NO
Polymer gels have been widely used for various wellbore service fluids, including fluids for conformance control of naturally fissured/fractured reservoirs. For an overview of existing polymer compositions, reference is made to the United States patent Nos. 5,486,312 and 5,203,834 which also list a number of patents and other sources related to gel-forming polymers.
Among the numerous cross-linking agents are inorganic ions (or ionic complexes) or polar organic molecules. When the polymer contains ionic groups such as carboxylate or sulphonate functions the polymer chains can be cross-linked by inorganic ions such as chromium(III) or zirconium(IV), frequently in the presence of monomeric ligands, such as acetate or adipate ions.
Furthermore, the gelation of high molecular weight polymers (Mw >
106 g/mol) has been extensively used in the development of water-based treatment fluids for water control is further described for example by R. D. Sydansk in "Acrylamide-polymer/chromium(III)-carboxylate gels for near weilbore matrix treatments", 7th SPE Symp. Enhanced Oil Recovery, Tulsa, Ok., April 1988, SPE/DoE 20214, or by R. S. Seright in: "Placement of gels to modify injection profiles", SPE/DoE Symp. Enhanced Oil Recovery, Tulsa, Ok., April 1994, SPE 27740. Typically for those methods, an aqueous solution of a high molecular weight polymer, such as a polyacrylamide/polyacrylate copolymer (a so-called partially-hydrolysed polyacrylamide), is gelled in situ in a porous formation using a metal cross-linker such as Cr3+ or small water-soluble organic cross-linkers such as formaldehyde and formaldehyde/phenol. Other water-soluble polymers such as poly(vinyl alcohol), the polysaccharide guar gum and the copolymer poly(vinylpyrrolidone-co-2-acrylamido-2-methyl-l-propanesulphonic acid) which can be cross-linked with a variety of cross-linking agents such as Zr4+ and boric acid.
A more recent approach is described by A. Keller and K. A. Narh in: "The effect of counerions on the chain conformation of polyelectrolytes, as assessed by extensibility in elongational flow: the influence of multiple valency", J. Polym. Sci.: Part B: Polymer Phys., 32, 1697-1706 (1994). It includes the cross-linking of poly(sodium 4-styrenesulphonate) using A13+ ions to form a gel. The concentration of the high molecular weight hydrophilic polymers used to form hydrogels is typically in the range 3-10 g/1.
Copolymers containing polar and non-polar segments are described for example in U.S. Patent No. 4,776,398. The copolymers are cross-linked in subterranean formations so as to control the permeablity of the formation layer before injecting a driving fluid into injector wells.
SUMMARY OF THE INVENTION
The present invention provides novel polymer for wellbore service fluids. Specifically the invention introduces novel cross-linking methods for such polymers avoiding the use of environmentally potentially hazardous agents. More specifically the invention provides polymer compositions for water control operations in hydrocarbon wells.
In one aspect, the invention provides a wellbore service fluid comprising polymers having a small amount of one or more repeat units incorporating a cross-linking group capable of forming chemical bonds with other polymers without additional monomeric cross-linking agents said fluid to be injected from surface location into a subterranean - 3a -location and being capable of forming a gel at said subterranean location.
In a further aspect, the invention provides a method of treating a subterranean formation penetrated by a wellbore, said method comprising the steps of preparing a wellbore service fluid comprising polymers having a small amount of one or more repeat units incorporating a cross-linking group capable of forming chemical bonds with other polymers without additional monomeric cross-linking agents;
injecting said wellbore service fluid from surface location through said wellbore into a subterranean location; and letting said service fluid form a gel at said subterranean location.
According to the invention there are provided a wellbore service fluid comprising polymers having cross-linking groups capable of 57.268 CA/NO
forming chemical bonds with other polymers without additional monomeric cross-linking agents.
Chemical cross-linking is defined as forming a chemical bond between the cross-linked polymers. Chemical cross-linking is understood to be stable and thermally irreversible. Polymers as within the scope of the present invention are defined as molecules having a molecular mass of more than 103, preferably more than 104.
A preferred embodiment of the invention comprises a polymer which consists of one or more repeat units incorporating a small amount (less than 3%) of a cross-linking monomer. Preferred cross-linking monomers include phenolic residues and/or aldehyde or alcohol groups.
The fluid under acid or base conditions can self condense creating a cross-linked gel of comparable strength to the already existing cross-linked polymer systems. The resulting gel has the same uses (conformance control etc.) as conventional systems but without the added environmental and toxicological hazards of the monomeric cross-linkers.
In a further embodiment of the invention two or more different types of polymer are used in combination. The different polymers containing mutually compatible groups for cross-linking.
In a further embodiment of the invention, the cross-linking reaction is initiated by altering the pH-value of the fluid.
These and other features of the invention, preferred embodiments and variants thereof, and further advantages of the invention will become appreciated and understood by those skilled in the art from the examples following below.
57.268 CA/NO
Chemical cross-linking is defined as forming a chemical bond between the cross-linked polymers. Chemical cross-linking is understood to be stable and thermally irreversible. Polymers as within the scope of the present invention are defined as molecules having a molecular mass of more than 103, preferably more than 104.
A preferred embodiment of the invention comprises a polymer which consists of one or more repeat units incorporating a small amount (less than 3%) of a cross-linking monomer. Preferred cross-linking monomers include phenolic residues and/or aldehyde or alcohol groups.
The fluid under acid or base conditions can self condense creating a cross-linked gel of comparable strength to the already existing cross-linked polymer systems. The resulting gel has the same uses (conformance control etc.) as conventional systems but without the added environmental and toxicological hazards of the monomeric cross-linkers.
In a further embodiment of the invention two or more different types of polymer are used in combination. The different polymers containing mutually compatible groups for cross-linking.
In a further embodiment of the invention, the cross-linking reaction is initiated by altering the pH-value of the fluid.
These and other features of the invention, preferred embodiments and variants thereof, and further advantages of the invention will become appreciated and understood by those skilled in the art from the examples following below.
57.268 CA/NO
MODE(S) FOR CARRYING OUT THE INVENTION
The invention can be exemplified in the case of a polymer containing an aldehyde (or alcohol) and a separate polymer containing a phenol used together to form a gel for use in conformance control.
The chemical reaction between aldehydes and phenols is a well documented process and is the basis for most organic cross-linking of polyacrylamide polymers to form gels. This reaction occurs under basic or acidic conditions and the gels formed are extremely strong and have many uses within the oil industry. The drawbacks to the use of these systems are that phenol is corrosive and causes burns and formaldehyde and other monomeric aldehydes are toxic or at the very least irritants. However, incorporation of these species onto the polymer chain eliminates their toxicity and greatly reduces their irritant properties, hence making for safer systems which are easier to handle.
A first example of a self cross-linking water-soluble polymer which consists of the monomer units acrylamide, acrolein and 4-vinylphenol according to the following structural formula c_I
~_I CH2_ I
H2 ' + H2 i {
X Y I ~
OH
-Z
formed by the copolymerisation of the monomers acrylamide (mole fraction X50.94), acrolein (mole fraction Y:50.03) and 4-vinylphenol (mole fraction Z50.03).
57.268 CA/NO
The invention can be exemplified in the case of a polymer containing an aldehyde (or alcohol) and a separate polymer containing a phenol used together to form a gel for use in conformance control.
The chemical reaction between aldehydes and phenols is a well documented process and is the basis for most organic cross-linking of polyacrylamide polymers to form gels. This reaction occurs under basic or acidic conditions and the gels formed are extremely strong and have many uses within the oil industry. The drawbacks to the use of these systems are that phenol is corrosive and causes burns and formaldehyde and other monomeric aldehydes are toxic or at the very least irritants. However, incorporation of these species onto the polymer chain eliminates their toxicity and greatly reduces their irritant properties, hence making for safer systems which are easier to handle.
A first example of a self cross-linking water-soluble polymer which consists of the monomer units acrylamide, acrolein and 4-vinylphenol according to the following structural formula c_I
~_I CH2_ I
H2 ' + H2 i {
X Y I ~
OH
-Z
formed by the copolymerisation of the monomers acrylamide (mole fraction X50.94), acrolein (mole fraction Y:50.03) and 4-vinylphenol (mole fraction Z50.03).
57.268 CA/NO
The condensation reaction between the phenol and the aldehyde still proceeds in a controlled manner to form the cross-linked gel and hence generate the desired water blocking system without the problems associated with the conventional systems which use separate (monomeric) cross-linking agents. An additional benefit of a self cross-linking polymer is that the cross-linking process is closely controlled and no screening out of the cross-linker or problems with mixing can occur.
The employment of two or more different polymer types containing different functionality allows for the gel time, gel strength and stability of the system to be controlled by varying the composition of the mixtures used as factors such as secondary cross-linking can be used advantageously.
The following example employs two polymeric systems. System A is a copolymer of acrylamide (mole fraction X!50.97) and acrolein (mole fraction Y50.03) in accordance with the following structural formula I I
CH2- ~ CH2- ~
j~NH2 O H
X Y
The second system (system B) is a copolymer of acrylamide (mole fraction X50.97) and 4-vinylphenol (mole fraction Z<_0.03) according to:
57.268 CA/NO
The employment of two or more different polymer types containing different functionality allows for the gel time, gel strength and stability of the system to be controlled by varying the composition of the mixtures used as factors such as secondary cross-linking can be used advantageously.
The following example employs two polymeric systems. System A is a copolymer of acrylamide (mole fraction X!50.97) and acrolein (mole fraction Y50.03) in accordance with the following structural formula I I
CH2- ~ CH2- ~
j~NH2 O H
X Y
The second system (system B) is a copolymer of acrylamide (mole fraction X50.97) and 4-vinylphenol (mole fraction Z<_0.03) according to:
57.268 CA/NO
H H
C
Ozz NHZ
X ~
OH
Z
The use of system A alone will produce a gel suitable for lower temperature systems but the use of a mixture of the two polymers will result in a cross-linked gel of much higher stability for deployment in harsher climates.
C
Ozz NHZ
X ~
OH
Z
The use of system A alone will produce a gel suitable for lower temperature systems but the use of a mixture of the two polymers will result in a cross-linked gel of much higher stability for deployment in harsher climates.
Claims (8)
1. A wellbore service fluid comprising polymers having a small amount of one or more repeat units incorporating a cross-linking group capable of forming chemical bonds with other polymers without additional monomeric cross-linking agents said fluid to be injected from surface location into a subterranean location and being capable of forming a gel at said subterranean location.
2. The fluid of claim 1, comprising polymers which consist of less than 3% of one or more repeat units incorporating a cross-linking group.
3. The fluid of claim 1 or 2, wherein the cross-linking group is selected from the group consisting of phenolic residues, aldehyde and alcohol groups.
4. The fluid of any one of claims 1 to 3, comprising at least two different polymers capable of cross-linking with each other.
5. The fluid of any one of claims 1 to 4, wherein in operation the polymers cross-link through a (poly)condensation.
6. The fluid of any one of claims 1 to 5, wherein in operation the polymers cross-link through a reaction initiated by changing the pH value of the fluid.
7. A method of treating a subterranean formation penetrated by a wellbore, said method comprising the steps of preparing a wellbore service fluid comprising polymers having a small amount of one or more repeat units incorporating a cross-linking group capable of forming chemical bonds with other polymers without additional monomeric cross-linking agents; injecting said wellbore service fluid from surface location through said wellbore into a subterranean location; and letting said service fluid form a gel at said subterranean location.
8. The method of claim 7, further comprising the step of changing the pH value of the fluid to initiate a cross-linking of the polymers.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB9726332.1 | 1997-12-13 | ||
| GB9726332A GB2332222B (en) | 1997-12-13 | 1997-12-13 | Gelling polymers for wellbore service fluids |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CA2255356A1 CA2255356A1 (en) | 1999-06-13 |
| CA2255356C true CA2255356C (en) | 2007-10-30 |
Family
ID=10823543
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002255356A Expired - Fee Related CA2255356C (en) | 1997-12-13 | 1998-12-09 | Gelling polymers for wellbore service fluids |
Country Status (4)
| Country | Link |
|---|---|
| US (1) | US6145592A (en) |
| CA (1) | CA2255356C (en) |
| GB (1) | GB2332222B (en) |
| NO (1) | NO328757B1 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8381814B2 (en) * | 2010-02-12 | 2013-02-26 | General Synfuels International, Inc. | Groundwater isolation barriers for mining and other subsurface operations |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3826311A (en) * | 1973-06-13 | 1974-07-30 | Calgon Corp | Producing well treatment |
| US3830302A (en) * | 1973-06-25 | 1974-08-20 | Marathon Oil Co | Method for improving oil-water ratios in oil producing wells |
| US4064940A (en) * | 1976-11-08 | 1977-12-27 | Continental Oil Company | Water control with polymers |
| US4532052A (en) * | 1978-09-28 | 1985-07-30 | Halliburton Company | Polymeric well treating method |
| US4776398A (en) * | 1985-01-31 | 1988-10-11 | Mobil Oil Corporation | Oil reservoir permeability control |
| US5015400A (en) * | 1986-10-09 | 1991-05-14 | Mobil Oil Corporation | Amino resins crosslinked polymer gels for permeability profile control |
| US4871021A (en) * | 1987-01-16 | 1989-10-03 | Mobil Oil Corporation | Block copolymers useful for enhanced oil recovery processes |
| US4773481A (en) * | 1987-06-01 | 1988-09-27 | Conoco Inc. | Reducing permeability of highly permeable zones in underground formations |
| US4947933A (en) * | 1989-01-03 | 1990-08-14 | Mobil Oil Corporation | Temperature activated polymer for profile control |
| US5203834A (en) * | 1990-12-21 | 1993-04-20 | Union Oil Company Of California | Foamed gels having selective permeability |
| US5061387A (en) * | 1991-01-16 | 1991-10-29 | Conoco Inc. | Aqueous gel system of partially methylated melamine-formaldehyde resin and polyvinyl alcohol |
| US5246073A (en) * | 1992-08-31 | 1993-09-21 | Union Oil Company Of California | High temperature stable gels |
| US5358051A (en) * | 1993-10-22 | 1994-10-25 | Halliburton Company | Method of water control with hydroxy unsaturated carbonyls |
| US5944106A (en) * | 1997-08-06 | 1999-08-31 | Halliburton Energy Services, Inc. | Well treating fluids and methods |
-
1997
- 1997-12-13 GB GB9726332A patent/GB2332222B/en not_active Expired - Lifetime
-
1998
- 1998-12-09 CA CA002255356A patent/CA2255356C/en not_active Expired - Fee Related
- 1998-12-11 NO NO19985826A patent/NO328757B1/en not_active IP Right Cessation
- 1998-12-11 US US09/210,038 patent/US6145592A/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| GB9726332D0 (en) | 1998-02-11 |
| US6145592A (en) | 2000-11-14 |
| GB2332222B (en) | 2000-01-19 |
| CA2255356A1 (en) | 1999-06-13 |
| NO985826D0 (en) | 1998-12-11 |
| NO985826L (en) | 1999-06-14 |
| NO328757B1 (en) | 2010-05-03 |
| GB2332222A (en) | 1999-06-16 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EEER | Examination request | ||
| MKLA | Lapsed |
Effective date: 20161209 |